A substrate inspection apparatus has been used for inspecting electrical characteristics of a semiconductor device formed on a wafer mounted on a substrate mounting table by supplying an electric current from a tester to the semiconductor device via a probe or the like. In some cases while inspecting a semiconductor device using the substrate inspection apparatus, a so-called batch contact test, in which electrical characteristics of a large number of semiconductor devices are simultaneously inspected by bringing probes into contact with the semiconductor devices formed on a wafer in batch, may be conducted.
However, in the batch contact test, a heat generation amount of the wafer may be, for example, about 300 W, which is larger as compared with a case where the individual semiconductor devices are sequentially inspected. As a result, an excessive amount of heat may be applied to the wafer, which may make it difficult to inspect the wafer at a desired temperature. For this reason, a substrate mounting table has been used that is provided with a coolant path circulating a coolant to absorb heat generated by the wafer.
However, in the above-described substrate mounting table, since the coolant path is formed in a spiral shape from a central portion to a circumferential portion of the substrate mounting table, it is likely that the central portion as an upstream side of a coolant flow is cooled further than the circumferential portion as a downstream side of the coolant flow. Therefore, it is likely that a temperature difference is generated between the central portion and the circumferential portion in a mounting surface of the substrate mounting table.